YR2 BB OVERVIEW Flashcards
Ganglion vs nucleus
Ganglion - PNS - one exception is the basal ganglia
Nucleus - CNS
Function of the basal ganglia
Regulate the intensity of movements
Inhibit antagonistic/unnecessary movements
Regulate attention and cognition
Motor program switch - from resting state
(Dorsal) striatum
Caudate + putamen
Corpus striatum
Striatum (c+p) + globus pallidus
Lentiform nucleus
Putamen + globus pallidus
Location of substantia nigra
At the base of the midbrain
Ventral striatum
Nucleus accumbens
Neurotransmitter input from cortex to dorsal striatum
Glutaminergic
Neurotransmitter input from substantia nigra to dorsal striatum
Dopaminergic
GABA excitatory or inhibitory?
Main inhibitory neurotransmitter of the CNS
D1 receptors excitatory or inhibitory?
Excitatory
D2 receptors excitatory or inhibitory?
Inhibitory
Summarise the direct pathway of the basal ganglia
a
What is the general action of the GPi on the motor thalamus?
Tonic inhibition of the motor thalamus to prevent sudden movement
Which direct or indirect pathway is tonically active?
Direct pathway
What is the function of the direct pathway
Allow for movement (?)
What is the internal capsule?
White matter structure separating the caudate from the putamen and the globus pallidus
Primary motor cortex is broadmann area…?
4
Location of primary motor cortex
Just anterior to the central sulcus
Distribution of the motor homonculous
Feet and legs centrally
Hip, trunk and shoulder
Hands and Fingers
Face
Arteries to the basal ganglia
Lenticulostriate arteries
Consequence of damage to premotor cortex or supplementary motor cortex
Apraxia
Effect on reflexes and muscle strength from apraxia
Normal reflexes and muscle strength
Apraxia
Inability to perform complex motor movement
Aphasia
Inability to understand or produce speech
Motor aphasia
Difficulty putting words together in a sentence - will use very simple or short sentences ( no problem understanding)
Consequence of damage to Broca’s area
Motor aphasia
Consequence of damage to FEFs
Oculomotor aphasia - difficulty moving the eyes horizontally and in following objects
Location of the somatosensory cortex
Parietal lobe
Location of prefrontal cortex
Right at the front of the frontal lobe (area 9)
Function of prefrontal cortex
Involved in the planning of movements and in executive functions
Consequence of damage to prefrontal cortex
Personality changes
Lack of ability to plan tasks
Location of orbitofrontal cortex
Most anterioinferior region of the frontal lobe (area 11)
Consequence of damage to the orbitofrontal cortex
Pseudopsychppathoc behaviour - impulsive, sexual disinhibition, lack of concern for others
Consequence of damage to the motor thalamus
Severe paralysis
Input into the corticobulbarpinal tract
a
Output from the corticobulbarspinal tract
a
Termination of the corticobulbar tract
a
Location of decussation of the corticospinal tract
aa
Function of corticobulbar tract
a
Pyramidal vs. extrapyramidal tracts
a
Which horns of the grey matter do pyramidal and extrapyramidal tracts run through?
a
Consequence of damage to the reticulospinal tract
a
Define spasticity
a
Define clonus
a
Define hyperrelexia
a
Cause of spasticity
a
Cause of clonus
a
Cause of hyperreflexia
a
What are spasticity, clonus and hyperreflexia signs of?
a
Decorticate vs decerebrate posturing - presentation and where is the damage?
a
What is the clasp knife reflex and what does this indicate damage to?
a
Three sites of DBS for treatment of PD
a
‘Folia’
a
Lobes of the cerebellum
a
Cerebellum - primary fissure
a
Function of cerebellar nodes
a
Function of spinocerebellar tract
a
On what side of the body will damage to the cerebllum show?
a
On what side of the body will damage to the cortex show?
a
Cerebellar nuclei
a
Function of vestibulocerebellum
a
Function of the spinocerebellum
a
Function of the cerebrocerebellum
a
What is the neocerebellum?
a
Input to neocerebellum
a
Output from neocerebellum
a
Floclonodular lobe syndrome (damage) presentation
a
Anterior lobe syndrome (damage) presentation
a
Posterior lobe syndrome (damage) presentation
a
Common cause of floculonodular lobe syndrome
a
Common cause of anterior lobe syndrome
a
Common cause of posterior lobe syndrome
a
Nystagmus/pstosis/constricted pupil of just one eye is a sign of what type of damage?
a
Symptoms of cerebellar stroke
aa
Define dysphagia
a
Define dysarthria
a
Define ataxia
a
Dorsal/ventral is anterior/posterior?
a
Dorsal/ventral spinocerebellum is ipsilateral or contralateral?
a
Two typical histological signs of PD
a
What are the three hallmarks of PD (signs)
a
What type of symptoms can DBS be used to treat?
a
NEED TO GO OVER THE DIRECT AND INDIRECT PATHWAYS ADN HOW THESE CHANGE WITH PD - ARUN/MIMI???
a
MPTP
a
Impact of MAO on dopamine
a
L-dopa to dopamine via which enzyme?
a
Amantadine to treat PD
a
Mutation in Huntington’s disease
a
What are the four different stages of pain?
a
Two types of nociceptors
a
TRPV1 nociceptor responds to?
a
TRPM8 nociceptor responds to?
a
ASIC3 nociceptor responds to?
a
Damage to which nociceptor fibres in diabetic neuropathy?
a
Two types of c-fibres
Peptidergic - release of peptides
Peptide poor - release of ATP
C-fibres project to which part of the lamina in the spinal cord and are carried in which tract?
a
D-delta fibres project to which part of the lamina in the spinal cord and are carried in which tract?
a
What is present in lamina II of the spinal cord?
a
What occurs in lamina V of the spinal cord?
a
Which part of the brain mediates the unpleasant sensation of pain?
a
Role of limbic system in pain?
a
Where do projection neurones decussate?
a
Function of the amygdala
a
Explain peripheral sensitisation
a
Four signs of inflammation
a
What is central sensitisation?
a
Define allodynia
a
Define hyperalgesia
a
Three signs of central sensitisation
a
Define chronic pain
a
Define maladaptive pain
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Two types of maladaptive pain
a
Define innocuous stimuli
a
Define endogenous modification
a
Example of endogenous modification
a
Gate control theory
The idea that non-painful input closes the gate to painful input
This prevents pain sensation from travelling to the CNS and so suppresses the level of pain that is felt
Neurotransmitters involved in central sensitisation
a
What are the three cortical components of the limbic system?
Cingulate cortex - anterior and posterior
Orbito-frontal cortex
Parahippocampal cortex/gyrus (medial temporal lobe)
Infarct to which arteries can result in damage to the limbic system?
Anterior cerebral artery
Posterior cerebral artery
Define caudal
Of or like a tail
Function of rostral anterior cingulate cortex
Registers that pain has occurred
+potentially what to do in response to this pain
Function of caudal anterior cingulate cortex
Registers the quality of the pain i.e. how bad on a scale from 1-10
Cingulotomy and function
Cut into the anterior cingulate cortex to prevent the rostro-caudal flow of fibres
Thought to reduce the emotional distress of pain
Function of posterior cingulate cortex
Unknown but thought to be involved in visuo-spatial memory
Function of parahippocampal cortex/gyrus
Involved in learning and memory
Function of orbitofronal cortex
How to behave in response to anticipated threat - how to avoid pain/injury
Overactivity of the orbitofrontal cortex is present in which neurological condition?
a
Subcortical components of the limbic system
a
Function of hippocampus
Time of day that memory occurred and location that the memory occurred AND the commitment of new memories to the long term memory
Anterograde amnesia and cause
Failure to transfer new experiences to long term memory
Damage to the hippocampus
Function of the amygdala
Stimulates feelings of fear and anxiety
Can also stimulate fight or flight response of the sympathetic NS
Werknicke-Korsakoffe syndrome and cause
a
Temporal lobe epilepsy and cause
a
Septum pallucidum
Thin vertical membrane - separates the anterior horns of the left and right lateral ventricles
Runs from corpus callosum to fornix
Septum pallucidum
Thin vertical membrane - separates the anterior horns of the left and right lateral ventricles
Runs from corpus callosum to fornix
Retrograde amnesia and cause
No access to the memories prior to an event - damage to the cingulate gyrus
Lenticulostriate arteries and origin
a
Lenticulostriate arteries and origin
Blood supply to basal ganglia and the internal capsule
Branches from the MCA
Vertebral arteries pass through which foramen?
Foramen magnum - then join to form basilar artery
Blood supply to the pons
Pontine arteries - branches from the Basilar
Blood supply to the brainstem
PICA - from the vertebral artery
Structures piercing the dura
Cerebral veins - bridging veins
Arachnoid granulation - CSF
MCA stroke presentation
a
ACA stroke presentation
a
PCA stroke presentation
a
PCA stroke presentation
a
ACA stroke presentation
Contralateral sensorimotor loss below the waist
Urinary incontinence
Personality defects
If the corpus callosum is effected - split brain synrome
PCA stroke presentation
Damage to the temporal lobe - reading and writing deficits, memory deficits
Contralateral homonymous hemianopia
Middle meningeal artery is a branch from which artery?
Third branch of the maxillary artery
Middle cerebral artery vs. middle meningeal artery
MCA - continuation of the internal carotid - anterior cerebral blood supply - medially located - within the brain - lentinculostriate arteries branch from here
MMA - blood supply to the meninges - branches from the maxillary artery - laterally located - runs just under the pterion - trauma here leads to extradural haematoma
Middle cerebral artery vs. middle meningeal artery
MCA - continuation of the internal carotid - anterior cerebral blood supply - medially located - within the brain - lentinculostriate arteries branch from here
MMA - blood supply to the meninges - branches from the maxillary artery - laterally located - runs just under the pterion - trauma here leads to extradural haematoma
Bones forming the pterion
Frontal, sphenoid, parietal, temporal
Cerebral falx and function
Septa (dural fold) between the left and right cerebral hemispheres
Cerebellum tentorium and function
Septa (dural fold) separating the occipital lobe from the brainstem
Tentorial notch and function
Hole in the cerebellum tentorium allowing for the passage of the brainstem and blood vessels to the middle cranial fossa
Two layers of the dura mater
Perisoteal layer - closest to the skull
Meningeal layer - next to the arachnoid layer
DO THIS QUIZ FOR DURAL VENOUS SINUSES
http://act.downstate.edu/courseware/haonline/quiz/practice/u5/quiztop5.htm
DO THIS QUIZ FOR DURAL VENOUS SINUSES
http://act.downstate.edu/courseware/haonline/quiz/practice/u5/quiztop5.htm
All layers of meninges from skull to brain
Skull Dura - periosteal layer Dura - meningeal layer Arachnoid granulations coming up from the arachnoid mater to drain into venous sinuses Arachnoid mater Subarachnoid space Pia mater Cerebral cortex of brain
Imaging bone - x-ray or MRI and why?
X-ray - bone is dense and absorbs high level of x-ray energy
Imaging CNS - x-ray or MRI and why?
MRI - mostly water - will not absorb x-rays
T1 weighted MRI - colour of bone, air, blood, CSF
Black
T1 weighted MRI - colour of fat and bone marrow
White
T2 weighted MRI - colour of bone, air, blood, CSF
White
T2 weighted MRI - colour of fat and bone marrow
Black
Lateral ventricle in relation to the corpus callosum
Immediately inferior
Fourth ventricle in relation to the cerebellum
Immediately anterior to the cerebellum and posterior to the brainstem/spinal cord
Consequence of enlarged brain ventricles
a
Define diffuse head injury
Microscopic damage which cannot be demonstrated by any of the current imaging techniques
BUT unconscious patient
Define diffuse head injury
Microscopic damage which cannot be demonstrated by any of the current imaging techniques
BUT unconscious patient
Depressed fracture
Area of skull driven inwards
Compound fracture
Scalp is torn
Closed fracture
The skin is not broken
Comminutive fracture
Fragmentation of bone into 2/3 pieces
Three theories for the pathophysiology of depression
Monoamine theory - serotonin and noradrenaline dysfunction
Dopamine - reduced levels
Decreased grey matter - at the subgenual cingulate prefrontal cortex
Which structure is impaired in depression, causing people to focus more heavily on negative thoughts?
Prefrontal cortex
Reversible MAO inhibitors are selective for what?
These are selective for MAOa
‘Antidepressant drug discontinuation syndrome’ + how to avoid this
Immediate cessation of antidepressants in some individuals can result in adverse side effects - should have a slowly reduced degree of the medication over time
What is bipolar disorder? + main treatment
Cycles of depression and mania (hyperactivity)
Lithium
How long should patients continue to take antidepressants for following remission?
At least six months to avoid relapse
When to use vagal nerve stimulation for the treatment of depression
Chronic depression
Advantage of CBT to treat depression
Can augment the pharmacological therapy for depression
Target of DBS for depression
Broadmann’s area 25/subgenual cingulate cortex
Depression can result in reduced white and grey matter in which structure?
Hippocampus
When should citrulline be used for treatment of depression?
SRRI - used in patients with heart arrthythmia’s/history of MI
Mechanism of action of tricyclic antidepressants
These act to reduce the reuptake of monoamines
Mechanism of action of SSRIs
Reduce reuptake or serotonin (5-HT) specifically
‘Cheese effect’
Inhibition of both MAOa and MAOb - should avoid certain foods which cannot be digested - consumption of these foods will result in adverse side effects
Which antidepressant drug is safe in overdose?
SSRIs
Fluoxetine - what is this and who should it be prescribed to?
SSRI
Used in patients with depression and diabetes - shown to have positive impact on HbA1c
Five key symptoms of depression
Anhedonia Feelings of guilt/lack of self-worth Weight loss/decrease in appetite Fatigue Lack of concentration
(suicidal ideation)
Give four non-pharmacological treatment options for depression
DBS
Vagal nerve stimulation
Electroconvulsive therapy
CBT
Structure of opioid receptors
G-protein coupled receptors
Three opioid receptors
Mu
Kappa
Delta
Location of opioid receptors
Throughout the body - widespread distribution results in wide range of effects
What are enkephalines?
Short morphine-like peptide produced naturally in the body
Involved in the regulation of nociception
Functions of morphine at receptor
Increased potassium conductance and decreased calcium conductance SO reduced excitability of neurone (hyperpolarised) and reduced release of neurotransmitters from neurone
Name four common opioid drugs
Morphine
Heroin
Dextromaride
Methadone
Opioid naxolone - what should you know?
This opioid/opiate (interchangable) has a very short half life - never leave patient alone with this
Three drastic side effects of opiodes
Respiratory depression
Nausea and vomiting
Hypotension
Opioid switch
Patients can become tolerant to opioids - should then switch to another type
Mechanism of action of paracetamol
Reduces the active oxidised form of COX-2
Analgesic and antipyretic
Mechanism of action of NSAIDs
Reduces COX-1 and COX-2 enzymes
Five adverse effects of NSAIDs
Arthritis - RA, OA Gout Nausea GI bleeding Muscle spasms
Medication types used in the treatment of neuropathic pain
Anticonvulsants
Tricyclic antidepressants e.g. amitriptyline
Name three anticonvulsants and the channels they work on
Sodium valproate - sodium channel
Carbamazepine - sodium channel
Pregabalin - calcium channels
Action of tricyclic antidepressants
Inhibit the reuptake of monoamines
Block both sodium and calcium channels
Trigeminal neuralgia
Facial syndrome involving one or more of trigeminal nerve branches
Compression/distortion/stretching
Symptoms of trigeminal neuralgia
Sudden, sharp, stabbing pain sensation
Treatment of trigeminal neuralgia
Carbamazepine
Baclofen
Phenytoin
Valproate
Mechanism of action of local anaesthetic
Block sodium channels
Substance P
Peptide released by the peptidergic nociceptive c-fibres
Released in response to infection/injury and promotes local inflammation
Which AEDs increase their own metabolism and how
Phenytoin and carbamazepine
These increase hepatic enzymes
Imperative treatment for status epilepticus
Intravenous benzodiazepine
Epilepsy
a
Different calcium channels
aa
Calcium channels most involved in epilepsy - what type of seizure?
aa
Action of pregabalin and gabapentin on epilepsy and mechanism of action
a
‘Epileptogenesis’
a
Stages of a tonic-clonic seizures
a
Safest AEDs to administer in pregnancy
a
Patient with epilepsy - how many of them will also have a relative with epilepsy?
a
Declarative vs. non-declarative memory
What memory form are these?
Declarative (explicit) - consciously going back in time to recall information
Non-declarative (implicit) - memory acquired and used unconsciously - skills and behaviours e.g. how to perform a dance
Long term memory
Two types of declarative memory and what are these?
Episodic - going back in time to remember personal events
Semantic - remembering general facts about the world
‘Spatial memory’ and region of brain involved in this
Memory related to where you are in space
Based on one’s environment and spatial orientation
(Taxi drivers - well developed)
Three types of amnesia and what are these?
Anterograde - cannot transform new events into long term memory
Retrograde - cannot remember events occurring prior to the onset of amnesia
Dissociative - cannot remember critical personal information about oneself
‘Long term potentiation’
The strengthening of synapses due to repetitive behaviours
Receptors involved in long term potentiation
NMDA glutamate receptors
Define consciousness
Ability to react appropriately to stimuli in the outside world
What does an EEG measure?
Voltages across the cerebral cortex
EEG appearance when awake and alert
Low amplitude and high frequency
EEG appearance when drowsy and close to sleep
High amplitude and low frequency
Two functions of sleep
Growth - release of growth hormone
Wound repair - effect on the immune system
Three effects of lack of sleep
Lack of concentration
Hypertension - risk of CVD
Obesity - reduced release of leptin and reduced sensation of satiety
How often do the stages of the sleep cycle repeat?
Stages 1-4 repeat every 90 minutes
Noradrenaline, serotonin and Ach levels when asleep vs. awake
These are high when awake and low when asleep
Function of REM sleep
Consolidation of memories
Removal of junk
Drugs to treat insomnia
Benzodizepines and Z drugs
Effect of dopamine on sleep
High levels of dopamine prevents sleep
Classical condition vs. operant conditioning
Classical - pairing of two stimuli to illicit a conditioned response
Operant - learning is controlled by consequences (negative and positive reinforcers)
Four components of classical conditioning
Unconditioned stimulus - food
Conditioned stimulus - bell
Unconditioned response - salivating in response to food
Conditioned response - salivating in response to bell
Define Garcia effect
Avoiding eating certain foods/drink due to a previous unpleasant experience
Define theory of tolerance
Ceasing of the conditioned stimulus does not stop the association between conditioned stimulus and response
Define social learning
Watching what other people do and how they are rewarded for this and copying their behaviour
What are the two most common waves seen in an ECG and when specifically are they seen?
Alpha - seen in most awake adults
Beta - seen in awake and alert (mental task) adults
What causes a change in alpha waves in an awake patient?
Alpha waves are neutral when eyes are closed
Opening of the eyes causes a change in the frequency and the amplitude decreases
Mental activity causes the amplitude of the alpha waves to increase
Alpha and beta waves when eyes are open vs. when eyes are shut
Eyes are closed - amplitude of the alpha waves is high and amplitude of beta waves is low
Eyes are open - amplitude of alpha waves is low and amplitude of beta waves is high
How is pain tolerance ratio calculated?
Experimental time (may be mean)/control time (may be mean)
